This application claims benefit of Japanese Application No. 2000-314356 filed Oct. 13, 2000, the contents of which are incorporated by this reference.
1. Field of the Invention
This invention relates to a camera film feed device and film feed method, and in particular, to a camera film feed device which automatically feeds the roll-shape film housed within a film magazine loaded into the camera, and a film feed method in this film feed device.
2. Description of the Related Art
Conventionally, when using a device for taking a photograph or a picture (hereafter called a xe2x80x9ccameraxe2x80x9d) to take photographs or similar, a film magazine in the interior of which is housed roll-shape film for photographing, in a wound state, must be loaded in advance into a prescribed position inside the camera.
After performing the operation of loading the film magazine into the camera, the film housed within this film magazine must be drawn outside the film magazine, wound by a takeup spool provided within the camera, and the roll-shape film must be placed in a prescribed position within the camera. Only after this series of operations (called film loading operations) is the camera in a state of preparation for taking photographs.
However, in the prior art there are cases in which, for example, the above-described series of film loading operations fails, and without noticing this, the user begins a series of photographing operations. In such cases, the camera user may for example notice that the film is not reliably wound by the takeup spool within the camera due to a phenomenon such as the absence of an operation to indicate the end of the film even when the prescribed number of image frames of the film has been exceeded.
In such cases, the photographing operations performed before failure of the film loading operations was noticed are all useless, and for the camera user, this represents the loss of rare photography opportunities.
The series of film loading operations for a conventional camera is, for general users, troublesome and difficult. Hence in the past, some experience has been required in order to reliably perform the operations to load a film magazine into a camera.
Conventional compact cameras and similar using roll-shape film employed in general use comprise a so-called auto-loading device, which is a film automatic feed device which, when the film magazine is loaded into the prescribed position within the camera, moves the film housed within the film magazine such that the film is at a prescribed photographing position within the camera.
However, even when using a camera comprising a conventional film automatic feed device, there are various problems due to which it may not always be possible to reliably load film.
General film automatic feed devices in conventional cameras are automated to some degree, but when loading the magazine at a prescribed position within the camera, there exists a procedure which the user must perform. This may be concretely explained as follows.
After opening the rear cover of the camera, the user loads the film magazine at a prescribed position in the camera interior, that is, in the magazine chamber. At this time, the user must place the tip area of the film tip vicinity (called the film leader, or simply the leader) within a prescribed range in the camera interior. If the leader is not positioned within this prescribed range, the film loading operations may fail.
Hence even in a conventional camera comprising a film automatic feed device, the problem that, depending on the user, film loading operations may result in failure, has not been completely resolved.
A first object of this invention is to provide a camera film feed device enabling the reliable placing of the roll-shape film housed within the film magazine in a prescribed position within the camera, using only more simple operations than in the prior art.
A second object of this invention is to provide a camera film feed device which alleviates the troublesomeness of film loading operations, and affords a satisfactory in use.
A third object of this invention is to provide a film feed method, in a camera film feed device, enabling the reliable placing of the roll-shape film housed within the film magazine in a prescribed position within the camera, using only more simple operations than in the prior art.
A fourth object of this invention is to provide a film feed method, in a camera film feed device, which alleviates the troublesomeness of film loading operations, and affords a satisfactory in use.
Briefly explained, the first invention is a camera film feed device enabling the freely loadable placement of a film magazine, having a takeup shaft on which is wound film and in which the film leader protrudes from a film feeding opening, and characterized in further comprising a magazine chamber in which to load the above film magazine; a fork joined to mate with the above takeup shaft of the above film magazine loaded into this magazine chamber; a takeup spool to take up the above film that is on the other side of the aperture for photographing opposite the above magazine chamber; a sprocket, positioned between the above magazine chamber and the above takeup spool; and a control circuit which controls the operation of the above fork, the above takeup spool, and the above sprocket; and wherein, when the above film magazine is loaded into the above magazine chamber, this control circuit starts operation to rewind the above film into the above film magazine by means of the above fork, and when the above film is rewound to a prescribed position stops the above rewind operation, and then starts operation to feed the above film to the above takeup spool by means of the above sprocket.
The second invention is a camera film feed device enabling the freely loadable placement of a film magazine, having a takeup shaft on which is wound film and in which the film leader protrudes from a film feeding opening, and characterized in further comprising a magazine chamber in which to load the above film magazine; rewinding means which joins to mate with the takeup shaft of the above film magazine and rewinds the film; takeup means, placed in an area on the other side of the aperture for photographing opposite the above magazine chamber, to take up film; feeding means, positioned between the above magazine chamber and the above takeup means, which feeds film from the above magazine chamber side to the above takeup means side; detection means which, when film is rewound by the above rewinding means, detects whether the film tip has reached a prescribed position; and control means which starts rewind driving of the above film through the above rewind means in response to loading of the above film magazine, stops film rewind driving by the above rewind means when the above film tip is detected by the above detection means, and then starts feeding driving by the above feeding means.
The third invention is a camera film feed device enabling the freely loadable placement of a film magazine, having a takeup shaft on which is wound film and in which the film leader protrudes from a film feeding opening, and characterized in further comprising rewinding means to rewind the film to a prescribed position in response to loading of the above film magazine; feeding means to feed the film toward the takeup spool after the end of the rewind operation by the rewinding means; takeup means to take up the film by means of the above takeup spool; and detection means to detect failure of a film feeding operation by the above feeding means, or failure of the film takeup operation by the above takeup means; and wherein, when failure is detected by the above detection means, the film is rewound again to the above prescribed position.
The fourth invention is a camera film feed device enabling the freely loadable placement of a film magazine, having a takeup shaft on which is wound film and in which the film leader protrudes from a film feeding opening, and characterized in further comprising rewinding means to rewind the film to a prescribed position in response to loading of the above film magazine; feeding means to feed the film toward the takeup spool after the end of the rewind operation by the rewinding means; takeup means to take up the film by means of the above takeup spool; winding means to wind the film in succession to an exposure operation; failure detection means to detect failure of a film feeding operation by the above feeding means, or failure of a film takeup operation by the above takeup means; end detection means to detect the fact that the film is wound until the end during winding operations by the above winding means; and control means which, when failure of the above feeding operation or failure of the above takeup operation is detected by the above failure detection means, rewinds the film such that the film leader is left outside the above film magazine, and when the film end is detected by the above end detection means, rewinds the film until the film leader is drawn completely into the above film magazine.
The fifth invention is a camera film feed device enabling the freely loadable placement of a film magazine, having a takeup shaft on which is wound film and in which the film leader protrudes from a film feeding opening, and characterized in further comprising rewinding means to rewind the film to a prescribed position in response to loading of the above film magazine; feeding means to feed the film toward the camera takeup spool after the end of the rewind operation by the rewinding means; takeup means to take up the film by means of the above takeup spool; winding means to wind the film in succession to an exposure operation; failure detection means to detect failure of a film feeding operation by the above feeding means, or failure of a film takeup operation by the above takeup means; an operation member to instruct that the film be forcibly rewound during photographing; output means to output a rewind signal in response to operation of this operation member; and control means which, when failure of the above feeding operation or failure of the above takeup operation is detected by the above failure detection means, rewinds the film until the film leader is at a prescribed position, remaining outside the above film magazine, and when a rewind signal is output by the above output means, rewinds the film until the film leader is drawn completely inside the above film magazine.
The sixth invention is a camera film feed device enabling the freely loadable placement of a film magazine, having a takeup shaft on which is wound film and in which the film leader protrudes from a film feeding opening, and characterized in further comprising rewinding means to rewind the film to a prescribed position in response to loading of the above film magazine; feeding means to feed the film toward the takeup spool after the end of the rewind operation by the rewinding means; takeup means to take up film which has reached the above takeup spool by the above takeup spool; first detection means to detect the film tip; second detection means to detect film perforations; and judgment means which, after a film feeding operation by the above feeding means, when the film tip is not detected by the above first detection means within a first prescribed time, or when, after the above first detection means detects the film tip within the above first prescribed time, the above second detection means does not detect a film perforation with a second prescribed time, or when, after the above second detection means detects a film perforation within the above second prescribed time, the above second detection means does not detect the next perforation within a third prescribed time, judges that the film feed operation has failed.
The seventh invention is a camera film feed device enabling the freely loadable placement of a film magazine, having a takeup shaft on which is wound film and in which the film leader protrudes from a film feeding opening, and characterized in further comprising feeding means to feed the film toward the takeup spool side in response to loading of the above film magazine; takeup means to take up the film by the above takeup spool; detection means to detect failure of the film feeding operation by the above feeding means or of the film takeup operation by the above takeup means; rewind means to rewind the film once again to a prescribed position, when failure of a film feeding operation or of a film takeup operation is detected by the above detection means; first detection means to detect the film tip during a rewind operation by the rewind means; second detection means, positioned closer to the above takeup means compared with the first detection means, to detect film perforations during a rewind operation by the rewind means; and, control means to control the rewind speed of the above rewind means according to the detection results of the above first detection means and the above second detection means.
The eighth invention is a camera film feed device enabling the freely loadable placement of a film magazine, having a takeup shaft on which is wound film and in which the film leader protrudes from a film feeding opening, and characterized in further comprising rewinding means to rewind the film to a prescribed position in response to loading of the above film magazine; feeding means to feed the film toward the takeup spool after the end of a rewind operation by the rewinding means; and takeup means to take up, by the above takeup spool, film which has reached the above takeup spool; and wherein the speed of feeding of film by the above takeup means is faster than the speed of feeding of film by the above feeding means.
The ninth invention is a camera film feed device enabling the freely loadable placement of a film magazine, having a takeup shaft on which is wound film and in which the film leader protrudes from a film feeding opening, and characterized in further comprising rewinding means to rewind the film to a prescribed position in response to loading of the above film magazine; feeding means to feed the film toward the takeup spool after the end of a rewind operation by the rewinding means; takeup means to take up, by the above takeup spool, film which has reached the above takeup spool; and, detection means to detect the movement speed of the film; and wherein the above takeup means switches the driving speed of the above takeup spool according to the film movement speed detected by the above detection means.
The tenth invention is a camera comprising a film feed device enabling the freely loadable placement of a film magazine, in which the film leader protrudes from a film feeding opening, and characterized in further comprising loading means to rewind the film to a prescribed position, and then feed the film toward the takeup spool, in response to loading of the above film magazine; rewinding means to rewind exposed film into the interior of the above film magazine; irradiation means to project infrared light toward the film; light-receiving means to receive light reflected from the film; nonvolatile storage means to store a prescribed value in order to judge the output level of this light-receiving means; and detection means to compare the output signal of the above light-receiving means with the above prescribed value, and detect the tip of the film; and wherein the output of the above light-receiving means is set to the next prescribed value, and stored in the above nonvolatile storage means, either with prescribed timing during loading by the above loading means, or after the end of operation by the above rewinding means.
The eleventh invention is a camera film feed device enabling the freely loadable placement of a film magazine, in which the film leader protrudes from a film feeding opening, and characterized in further comprising light projection/reception means, provided within the film feed path, which projects infrared light toward the film, and which receives light reflected from the film and outputs a light-reception signal; nonvolatile storage means to store a prescribed value for use in judging the output level of the light-reception signal output from this projection/reception means; detection means to compare the above light-reception signal and the above prescribed value, and detect the presence or absence of film; loading means to feed film in response to loading of the above film magazine; detection means to detect the failure of film loading by this loading means; and rewinding means to rewind the film if failure of the above film loading is detected by this failure detection means; and wherein the above light-reception signal output is stored in the above nonvolatile storage means as the above prescribed value in response to the end of a film rewind operation by the above rewinding means upon occurrence of the above failure.
The twelfth invention is a camera film feed method enabling the freely loadable placement of 135 millimeter film, characterized in comprising a step to detect the loading of the above film magazine; a step to rewind the film until the film tip reaches a prescribed position when loading of the above film magazine is detected; a step to feed the film toward a takeup spool after the end of this film rewinding step; and a step to take up the film by the above takeup spool when the film is fed as far as the position at which the above takeup spool is placed.
The thirteenth invention is a film feed method for a camera enabling the freely loadable placement of a film magazine, having a takeup shaft on which is wound film and in which the film leader protrudes from a film feeding opening, and characterized in comprising a step to detect the loading of the above film magazine; a step to rewind the film until the film tip reaches a prescribed position when loading of the above film magazine is detected; a step to feed the film toward a film takeup spool after the end of the above rewinding step; a step to take up the above film by the above takeup spool when the film is fed as far as the above takeup spool; and, a step to rewind the film tip to the above prescribed position if failure of the operation of the above feeding step, or failure of the operation of the above takeup step, is detected.
These inventions, and other objects and advantages of the same, will become more clear from the following detailed explanation.
By means of this invention, a camera film feed device and camera film feed method can be provided which enable the reliable placing of the roll-shape film housed within the film magazine in a prescribed position within the camera, using only simpler operations than in the prior art.
Also, by means of this invention, a film feed device and film feed method can be provided which alleviate the troublesomeness of film loading operations, and which can afford a satisfactory in use.